Incremental image decoder for a specific image format. ... List of all member functions. virtual  ~QImageFormat  ()  . ... By making a derived classes of QImageFormatType which in turn creates objects that are a subclass of QImageFormat, you can add support for more incremental image formats, allowing such formats to be sources for a QMovie , or for the first frame of the image stream to be loaded as a QImage or QPixmap . ... New subclasses must override this method. ... qasyncimageio.h: 1998/07/03 . ...